The objective of this paper is to analyse reduction in wind power variability through aggregation and use of energy storage systems. A key focus is to evaluate the impact of regulatory framework in addition to the capital expenditure to ascertain techno-economic feasibility of energy storage systems in wind farm applications. A generic techno-economic is developed which takes into account the effects of regulatory framework in addition to the technical and economic features of storage options. Existing wind farms from South Australia are used as test cases. First, a detailed quantitative analysis is performed to establish the variability associated with individual wind farms and the aggregations of their power outputs. Then, the appropriateness of a number of existing energy storage types are evaluated using the developed techno-economic model. Relationships between wind farm sizes, wind farm variability levels, storage capacity requirements, storage costs and storage payback times are determined and discussed for both current and potential future economic and regulatory scenarios. It is found that regulatory framework can be of paramount importance in ascertaining the economic feasibility of energy storage. For example, if the ramp-rate violation penalty (determined to be $8.89/MW/min) is doubled, then the payback time of energy storage capital investment is found to reduce from 5.32 years to 2.52 years. It is also found that larger wind farms require smaller energy storage capacity and smaller wind farms generally results in a shorter energy storage system payback times.

Recent works have addressed the analysis of some situations that alter the gearbox oil results in wind energy conversion systems (WECS). This work contributes by completing the analysis of additional situations, based on key operational data collected from 10 different multi-megawatt wind turbines at two different locations with two top-tier technologies, and has demonstrated that the oil analysis results can be altered in practice. As important as detecting these situations is to verify how the data collected by the different operators and transferred to the laboratories, this relevant information is not included in most cases. The issues that can stem from this lack of valuable data can be mitigated with a new and more complete template. This paper proposes a detailed template that is ready for an industrial use and contributes to standardizing the information handled by all actors. The suggested template, which is designed based on extensive experimental results and an in-depth analysis, provides detailed information for laboratories to improve conclusions, recommendations and action plans. The investigation provides a high archival value for researchers whose investigation deals with gearbox oil maintenance. Furthermore, the global impact of the proposal on the wind industry can be very relevant in terms of benefits and it will ultimately be an advance in the evolution of the operation and maintenance of wind farms.